Android关闭多个Activity的实现方法

public class App extends Application { 

  private static List lists = new ArrayList<>(); 

  public static void addActivity(Activity activity) { 
    lists.add(activity); 
  } 

  public static void clearActivity() { 
    if (lists != null) { 
      for (Activity activity : lists) { 
        activity.finish(); 
      } 

      lists.clear(); 
    } 
  } 
} 

//然后写一个基类Activity，在构造构造方法调用App.addActivity(this);就可以实现。

public class BaseActivity extends AppCompatActivity { 

  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    IntentFilter intentFilter = new IntentFilter(); 
    intentFilter.addAction(getString(R.string.promotion_action)); 
    registerReceiver(receiver, intentFilter); 
  } 

  BroadcastReceiver receiver = new BroadcastReceiver() { 
    @Override 
    public void onReceive(Context context, Intent intent) { 
      finish(); 
    } 
  }; 

  @Override 
  protected void onDestroy() { 
    super.onDestroy(); 
    unregisterReceiver(receiver); 
  } 
} 

//销毁所有的Activity 
//关闭本窗口
getActivity().finish();

//关闭父窗口
if(getActivity().getParent()!= null){
  getActivity().getParent().finish();
}

//关闭列表页面
Intent intent = new Intent();
intent.setAction(getString(R.string.promotion_action));
getActivity().sendBroadcast(intent);

public class BaseActivity extends AppCompatActivity { 
  protected final static int RESULT_CLOSE = 0; 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
  } 

  @Override 
  protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    if(resultCode == RESULT_CLOSE){ 
      setResult(RESULT_CLOSE); 
      finish(); 
    } 
  } 
} 

intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 

@Override 
public boolean onKeyDown(int keyCode, KeyEvent event) { 
  if (keyCode == KeyEvent.KEYCODE_BACK) { 
    //销毁所有的Activity 
    Intent intent = new Intent(this,FirstActivity.class); 
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
    startActivity(intent); 
  } 
  return super.onKeyDown(keyCode, event); 
} 

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_TASK_ON_HOME); 

/* 
  FLAG_ACTIVITY_CLEAR_TASK 这个标示将在这个活动开始之前清除该栈中所有的任务,将里面的Activity都finish掉 
  FLAG_ACTIVITY_TASK_ON_HOME 这个flag将造成新任务在home的上面，就是在启动的Activity点击back之后就会回到home界面 
 */